Thermostatically-governed electric laundry iron



Oct. 28,1930'. G. BROWNING v 379,960

THERMOSTATIGALLY GOVERNED ELECTRIC LAUNDRY IRON y Filed June 17. 1929 5sheets-sheet 1 Oct. 28, l1930.

G. BROWNING THERMOSTATICALLY GOVERNED ELECTRIC LAUNDRY IRON Filed June1'7. --1929 3 Sheets-Sheet 2 or efo @www J5 jgazfaya Oct. 28, 1930. G.BRowNlNG `1,779,960

`'I'HERMOSTT@ALLY GOYERNED ELECTRIC LAUNDRY IRO I Filed June 17. 1929 ssheets-sheet s @deze for A 'eoye .Erozafzzjf @BAULE/1 @MMT PatentedOct.. 28, 1930' UNITED.STATESV PATENT oFFlc-E GEORGE BBOWNING, OF'WILMETTE ILLINOIS, ASSIGNOR TO CHICAGO FLEXIBLE SHAFT COMPANY, OFCHICAGO, ILLINOIS, ACORIORATION F ILLINOIS THERMOSTATICALLYTGOVERN EDELECTRIC LAUNDRY IRON I Application led .Tune 17,

The purpose of this invention is to provide an improved construction ofan electrlc laundry iron having thermostatic devices for au tomaticallygoverning the temperature of the iron by 4automatically interrupting thecircuit by which it is energizedv when any predetermined temperature isobtained, and automatically restoring the circuit connection when thetemperature falls below such prem determined degree, with manuallyaccessible and operable means for adjusting the thermostatic devices tovary at will a predeter- Figure 1 is a top plan view of an electric llaundry iron embodying this invention, with the hand piece of the handlemember reonthe handle strap.

moved.

Figure 2 is a section at the line 2-2 on Figure 1.

Figure 3 is a fragmentary view consisting of a part of Figure 2 showingthe parts of -a thermostatic regulating device in dierent position fromthat shown in Figure 2.

Figure 4 is a plan view with the handlev and cover or enclosing shelland the heat storing member removed, and the upper sheath of the heatingunit partly 'broken awayto show the heating coils.

Figure 5 is a plan view with the handle d' and .enclosing rshellremoved, and the heat storing member partly broken away to show theheating unit below it. v YFigure 6 is a sectionat the line 6-6 on Figure2, with [the handle upright lpartly broken away to reduce the view.Figure 7 is a section at the line 7-7 on Figure2.

Figure 8 is a bottom plan View of the handle and certain adjustableparts carried Figure 9 is a perspective view of a frame which is mountedon the sole plate :Eorcarry-l ingfthe thermostaticgoverning device.

Figure 10 is a section at the plane indicated 1929. Serial No. 371,356.

Referring to the drawings A-is the sole plate,the bottom member of thebody of the iron having the working face. D is the heating unit mountedupon the upperside of the sole plate. C is a heat storage member mountedabove the heating unit and servingl to hold the latter tightly uponv theupper surface of the sole plate. J is a cover or enclosing shellhereinafter referred to as the cover shell. .E is the handle comprisinga hand piece, El, and a handle strap, E2, having uprights, e2, at theupper end of which the hand piece is carried. A socket for holding theplu carrying the circuit'wires leading to and rom the source of currentis seen at F. F1 and F2 are the plug-carrying circuit wires leading toand from the source of current as seen at F. F1 and F2 are theplug-engaging circuit terminal pins; f1 and f2 are flexible 4metalstrips constituting initial parts of the circuit connections rom thepins, F1 and F2, respectively, to the heating coils, D1, in the heatingunit, D, said connections from the strip, f2, beingmade throughthermostatically governed switch devices hereinafter described andexplained.

For accommodating the thermostatic regulating devices with their severalparts in proper relation respectivel and the heat storage member, thesole plate is formed with a recess,a, in its upper face, and the storagemember, C, is formed with a recess, c, in its lower face, registeringwith the recess, a, butv somewhat more extended laterally than thelatter. For mounting the thermostatic -re ulating devices in therecesses, lai and c, t ere is provided a frame, G, mounted upon thesole'plate, overhanging the recess, a, of the latter, and extending upinto the recess, c, of the VStora e member. This frame, G, comprisesuprig t lateral webs, 10, extendin uninterruptedly over the entirelength o the frame, and connected at their upper edges by transversewebs, 11,11, each extendin for a short portion only of the length o? theframe, leaving between them to the sole plate suit-ably extended openins for connections, hereinafter described, which are provided foradjustin the thermostatic regulat-ing dvices. The tfyrame, G, is mountedon the sole plate by means of laterally projecting lugs, 12, 12,provided at the lower edges of the upright webs, 10, 10, the sole platehaving in its upper surface'recesses, 12, in which the lugs, 12, areseated, secured to the sole late by screws, 13, ,13, screwed throu hsaidp lugs into the sole plate. This frame, is conveniently arranged forcarrying vthe plug socket, F, as may be understood from Figure 2.

The thermostatic devices for controlling the operation for maintainingthe iron at predetermined temperature will now be described.

These devices comprise a bi-metallic bar, H, hereinafter referred to asa thermostat, said thermostat being rigidly, but adjustabl secured atone end insulatedly to the so e plate by means of a mounting fittingconsisting of a U-shaped stamping, 17 having parallel limbs, 17, 17,extending inside ,the upright side webs, 10, 10, of the frame, G, andpivoted thereto as seen at 17", said fitting having an arm, 17 c,extended from the cross l for connectin web of its U-form, said arm at ashort distance from said cross web being bent iirst upwardly and then tothe right, as seen in Figure 2,V and having its extremity secured to thesole plate by belng fastened by a. screw, 17, to the top of a post, 17which is screwed into the sole plate and adapted to be adjustedvertically by screwin it more or less into the sole late, for w ichpurpose it has a hexagona` -head, 1'7. The thermostat, H, is securedinsulatedly to the fitting 17, by bolts, 19, 19, which alsosecureinsulatedly to the fitting and conductively to the thermostat aconductive bracket 20, which is rovided the thermostat con uctively withthe heatlng coil, said connection being effected by the iexibleconductor f,above mentioned leadin from the coil and secured to thebracket, 20, ya binding screw, as seen at 21. 4

The thermostat, H, is insulated from the U-shaped fitting, 17 by meansyof a mica strip, 25, interposed between said fitting and thethermostat, as seen in Fi re 2. The

bracket, 20, is insulated vfrom tl e fitting, 17

by a mica strip, 24, as seen in Figure 2, and the cross web of theU-form of the fitti'n 17 has the-apertures through which the olts, 19,19, extend enlarged for am le clearance around the bolts, so that theatte'rido not eilect electrical conduction from the'bracket, 20,to saidfitting, 17. .4

And the bolts, 19, having their heads binding the under side of thethermostat and their nuts, 19, clamping a the upper side of thehorizontal arm of the bracket, 20, constitute effective conductors forthermostat carries and at which they areb washer plate, 26, onto thecurrent from the bracket, 20, to the thermostat.

The mica strip, 24, is extended alon entire length o the thermostat, an

the the button, 30, at the end of a spring arrn, 31, made fast at theother end to the free end of the thermostat.

at its free end a contact- The purpose of this spring A mounting for thecontact button will be hereinafter explained.

For cooperating with the thermostat in the regulation lof thetemperature of the iron, there 'is' provided a cooperating contact carrier, 40, ivotally ,mounted at one end in the frame, on the pivot pin,17 said contact being` carried at the end of a conducting strip, 42,mounted insulatedly on the contact carrier, said insulation beingeffected by a mica strip, 43, inter osed between the contact carrler,40, an the conductin strip, 42, the conducting strip being secure to thecontact carrier by rivets, 44, 44, insulated from thecarrier, asindicated by insulations consisting of mical washers, 45, interposedunder the rivet heads, as seen in Fi res 2 and 3. The conducting strip,42, which carries the contact, 42, is connected in circuit with theheating coil by means'of a flexible conductor shown at 46, which isclamped at one end between the insulating mica strip, 43, and theconducting strip, 42, and connected at the other end to circuit terminalpin, F, as seen in Figure 2.

For holding the cooperating contact carrier, 40, in definite position,and for ad'usting it to vary the temperature limit at w ich the circuitis interru ted, there is provided a bell crank lever, 50, ulcrumed atits an le on a fulcrum pin, 49, mounted in opposite y -positioned lugs,53, 53, grgojecting up from the upper edges of the we G, said leverhaving a 51, extending between the webs, 10, 10, of the frame, G,longitudinally of said frame reflexed upon itself to form a'slot,y 51,an engaging in said slot is a pin, 55, mounted in upstanding lugs, 56,56, which are folded up from the opposite edges contact carrier, 40, theupstanding arm of the bell crank lever being extended up through anaperture, 57, in the heatstora e member, C, and arranged at its upper enfor actuation by a manually operated device which is mounted upon thehandle strap, E and projects down throu h said strap and through 'thecover shell, for engaging said bell crank lever, as will be hereinaftermore particularly described.

U n considering the far escribed andas shown in the drawings, it

construction as thus 10, 10, of the frame, relatively short am,

of the cooperating may be understood that at normal atmosi temperature'which may be hereinl-,Ifte'r` adapted to become straight as seen inFigure' 3 when heated to the predetermined temperature limit at whichthe circuit is to be interrupted for preventing further rise intemperature. And it will be understood that at the positioncorresponding to cold temperature of the iron, and at any position towhich the cooperating contact button, 30, is intended to be adjusted,the contact button, 42a, is at such osition that the thermostat in itsnormally exed form holds the contact button, 30,.in contact with thecontact button, 42, with the spring arm, 31, flexed as seen in Figure'2and'reacting resiliently for stressing the contact button, againstthelcontact button, 42, And it will be recognized, therefore,

that the two cont-act buttons will remain in contact, keeping thecircuit closed and the heating unit energized until the thermostatbecomes heated to a degree at which it will be .straightened enough totake up -the resilient action'of the spring stem, 31, of the contactbutton, 30; and that upon becoming heated beyond this point and furtherstraightened it will withdrawn the contact button, 30, from the contactbutton, 42', and cause the circuit to be interrupted. And it will berecognized that upon this interruption and the cooling of the iron andthe thermostat which will follow upon the-thermostat becoming slightly icooled will again carry the contact button, 30,

into contact with the button, 42", closing the lcircuit connection `andcontinuing the heating and maintaining the temperature of the iron tothe maximum for whichthe adjustment is made. The result is that when theiron is in use so as to utilize the heat by radiation or conductiomthecircuit will remain closed as long asi-the utilized heat substantiallyequals the heat generated by the heatingy unit; and that when thecircuit is interrupted in the manner described by the mo- A mentary riseof the temperature beyond the predetermined degree, if the conditions ofuse are such as to cause continued radiation of the heat, causing theiron to become cooled below the limit, the circuit will be immediatelyclosed, and if the heat generating capacity of the heating unit issubstantially equal to the capacity of the iron for giving off-heat byconduction or radiation, there will result a rapid succession ofopenings and closings of the circuit, with the practical eiect of acontinually closed circuit, with unappreciable variation of thetemperature, causing the generation of the precise amount of heatutilized by loss of radiation from the iron. v

Figure 3 shows the contacts, 3() and 42,

and the thermostatat substantially straight position which maybeunderstood to bethe position and form ofthe thermostat, at the maximumtemperature.` This figure may be understood as intended to show theadjustingdevices set vfor holding the coperating contact -Q carrier atposition for medium temperature.`

that the iron has been operating at high teml perature and the operatorhas adjusted the adjusting devices to the low or lower temperat-ure, asmedium, thereby causing the contacts to be separated; and that theywill" remain thus separated until the thermostat cools downapproximately to the temperature for which the adjustment is made, thiscooling causing the thermostat to become flexed for carrying the contactbutton, 30, up into contact again with the contact button, 42a, causingthe circuit to be closed and the heating unit energized for maintainingthat temperature.

It may be understood from the foregoing description that for theordinary purposes of a laundry iron the adjusting devices willbearranged so that at the adjustment for the lowest temperature at whichthe iron is to be operatedthe circuit will be closed-that is, thebuttons will be in contact-when the iron is cold, so that whenthe ironis connected by the plug in the usual manner with the source riseottemperature to said lowest temperature limit at which the iron is tobe operated; and that the structure may operate in this manner is thepurpose of the spring stem, 31, of the-contact, 30.

Upon careful consideration rof the structure it may be recognized thattheprinciple of operation of the thermostat requires that it should belixedly held at one end so that the change of form due to change oftemperature shall cause the movement of the free end at which thecontact is carried tobe definite and to correspond always to thetemperature change, as could not be depended u on to be the case if theother end could per orm art of the movement. And it will be recognizedalso-that the temperature at which the contacts will separate depends,to a considerable extent, on the range ofthe resilient action of thespring stem, 31, of-th'e contact, 30, and the extent to which it isflexed or straightened from the lnormalorm at the normal position of thearts as assembled at normal atmospheric temperature. And it will berecognized that the slight and unavoidable variations in the stiffnessof the spring stem and .in its normal form, as being straight orslightlycurved, will make it extremely diilicult to limit at which the contactswill separate at any given adjustment of the cooperating contactcarrier, as at High or Low. It 1s in view of these considerations thatthe thermostatis mounted as described, so that it is adjustable at itsrigidly secured end by setting the threaded post, 17, more or lessdeeply into the sole plate.

The manually operable adjusting devices for setting the thermostatic.devices to vary the redetermined temperature limit will now e described:

These adjusting devices comprise a slide, 60, on the horizontal portionof the handle strap, said slide being mounted upon the upand Low; andthe slide has a reading slot,

70, through which these markings may .be read at the positionsrespectively of the shde corresponding to the temperature indicated.

The slide carries an operating stem, 63, which is mounted in a bearing,62, .formed at the center of an up-struck hollow boss, 62, of the slide.Said stem' extends down through a longitudinal slot, 68, in the handlestrap and through a correspondingly positioned slot, 82, in the covershell, J, and engages at its lower end the upper end of the upstandingarm ofthe bell crank, 50, as seen in Figure 2 and heretofore mentioned.The operating stem, 63, is provided at its upper end with an operatingknob, 64, which is itself jourvnaled on the bearing, 62, for assistingin holdin the operating stem accurately in the vertica ositlon. The oerating stem carries rigi with it under t e hollow boss, 62, a disk, 65,having a rigidly projecting pin',

66, which engages a short transverse slot, 67,

in the handle strap opposite the middle point of the length of the slot,68, in which the operating stem, 63, moves for operating the bell cranklever, 50. Upon considering thisv construction it will be understoodthat upon rotating the handle, 64, the pin, 66, becomes a fulcrum aboutwhich said disk swings as it is rotated by the handle, the pin, 66,moving in thetransverse slot a distance corresponding to the height ofthe segment defined by the arc of movement of the pin about the centerof its rotative movement, viz., the operating stem, 62; and thataccordingly with.

only an amount of movement of the pin trans- 1 versely of the handlestrap equal to the height of that segment, there is obtained longitudinal sliding movement of the slide, 60, equal to the chord of the arc ofsaid segment, which is sufiicient for shifting the slide through yhandle strap.

Certain specific details of the construction which are of verysubstantial importance from the standpoint of economical manufacturing,convenient assemblage, and rigidity of the parts foroperating` the ironinlaundry service, will now be described.

The frame, G, which, as above described, is secured very rigidly andfirmly to the sole plate, A, and carries the plug socket, F, has mountedri 'dlyin the transverse webs, 11,

11, upstanding threaded posts which extend through suitable apertures inthe heat storage member, C, in which said posts fit snugly, and nuts,A81, 81, screwed onto said threaded posts serve to clamp the heatstorage member, C, firmlydown onto the heating unit, thereby clampingthe latter firmly on the sole plate, A. These threaded posts, 80, 80,extend up to suitable height for serving as means .of mounting thehandle, which is affected by cap nuts, 85, 85, taking through suitableapertures in the handle strap which the heads of the ca nuts engage, andscrewed onto the upper en s of the threaded posts as seen in Figure 2.The handle is thereby rigidly connected to the frame, G, which in turnis rigidly secured to the bottom member,- the sole plate, A,-so that allthe parts are clamped `to ether between the handle strap above and t esole plate atv the bottom. y

The same connections serve for securing firmly in place the cover shell,J said cover shell -being dimensioned for seating at its lower edge onthe margin of the sole plate and havinglapertures positioned forregistering with t e upstanding threaded posts, 80, 80, and dimensionedfor admitting the cap nuts, 85, which thus serve to clamp the handlestrap down onto the cover shell, the latter being desirably formed withup-struck bosses, 85, at which the apertures are formed for admittingthe cap nuts, thus serving to space the handle strap up from the generalsurface of the cover shell, aiording clearance between -the handle strap'and the top of the cover shell for the clasping lugs of the slide, 60,and for the end of the pin, 66, protruding through the slot, 67.

- I claim:

1. An'electric laundry iron having in comblnation with a heating unitand a sole plate on which the heatin unit is mounted for heating theplate, a so e plate havin a recess 1n the .upper side at a portion o itsarea which is not occu ied by the heating unit; a

heat storing mem r lodged' upon the heatf ing unit and having a recessin its lower side registered with the recess of the sole plate, a

frame mounted by securement to the sole plate and .extending in thevertical zone of the recess of the latter and into the recess of theheat storing member, thermostatic means mounted on said frame comprisingcooperatin contacts which are arranged to be separate for interruptingthe circuit which energizes the heating unit, at predeterminedAtemperature of the thermostatic member of said thermostatic devices, anoperating handle for the iron, a mounting strap for the same, andmounting posts for said strap carried by saidl frame and extending upthrough the heat storing body member for securement o-f the handle strapthereto above said heat storing member, connections for adjusting thethermostatic devices to vary the temperature limit determined thereby,said connections extending' up through the heat storing member, andmanually operable means for actuatin said connections mounted upon thehan e strap above the same.

2. An electric laundry iron having in combination with a heating unitand a sole plate on which the heating unit is mounted for heating theplate a sole plate having a recess in the upper side at a portion of itsarea which is not occu ied by the heating unit; a

heat storing mem er lodged above the heating unit having a recess in itslower side registering with the recess of the sole plate, a

frame mounted by securement to the vsole l plate and overhanging therecess Iin the latter, said frame comprlsing lateral longitudinallyextending webs and transverse web portions connecting ythem at the upperside of the frame; thermostatic means comprising a thermostatic element,and co-operating contact carrier carried by said frame between its saidlateral longitudinall extendin webs, the thermostatic element geingcarri by the framev depending in the recess of the 5 sole plate, where yit is exposed immediately to the heat ofthe sole plate, and the co-orating contact carrier being positioned a ve the plane of the heatinunit, whereby it is exposed limitedly to t e heat radiated by the soleplate and heat .storin member, the latter having an aperture lea ng fromsaid recess in its lower side through the upper 'side of said member;connections for operating the co-operating contact carrier of thethermostatic device extending up through said aperture, a handle havingits supporting strap mountedabove the heat storing'member, and manuallyoperable means `mounted on said strap above the same and extendingtherethrough for engaging and actuating the connections which extend upthrough said aperture of the heat storing member.

3. A n electric iron container, a base mem- Y ber having the workingface of the iron, a heat-storing member above the base member,

and a heating unit between the two members; thermostat regulating meansarranged to automatically open and close the circuit at ythrough theheat storage member, stops mounted on said posts above the said storagemember for clamping the latter onto the base member and the heatingunit, and a handle support secured to the upper end of said posts.

4. An electric iron container, a base member having the working face ofthe iron, a heat-storing member above the base member, and a heatingunit between the two members; thermostat regulating means arranged toautomatically open and close the circuit at predetermined temperature, aframe mounted between the sole plate and the storage member forsupporting the thermostatic device; posts extending rigidly from saidframe up through the heatl storage member, stops mounted on said postsabove the said storage member for clampin the latter onto the basemember and the eating unit, a cover shell enclosing the heat storage,member and the heating unit and stopped at its lower edge on the marginof the base member, havin apertures aligned with the posts, and a han lesupport lodged above the cover shell having bolt holes aligned with theholes of the cover shell yand nuts applied to the bolts arran ed to besto pcd on the handle support an there to c amp the latter onto thecover shell an the cover shell onto the base member in securing thehandle to the posts, and thereby to the frame and also to l thebasemember, clamping all parts of the iron firmly together.

In testimon whereof, I have hereunto set my hand' at June, 1929. GEORGEBROWNING.

cago, Illinois, this 7th day of

